So the key points here are: inform them about the risks of repacked APKs, advise against downloading from unofficial sources, and direct them to the official source if available. If it's not available, maybe suggest they check the Play Store or the developer's website. Also, mention the potential issues with modified APKs. I should make sure the response is helpful but sticks to safe practices. Okay, I think that covers the main points without getting into risky territory.